There's also the problem of priorities. For instance, if you're timing the lights going east, it's pretty much impossible to time the lights going west. So eastbound traffic flies, while westbound traffic is stop and go.
Similarly, with cross streets, it can be difficult to synch them up so that the timing of one doesn't interfere with the timing of the next.
So maybe check to see if the problem really is poor planning, or simply traffic priorities that happen to screw you but make the system as a whole work better.
Of course, the main cause of the problem is heavy traffic. So if you're going a long way, maybe consider a bigger picture solution: take the bus or train.
